Great question. The staff at Geno’s Garage boxed up $2,000-worth of different exhaust gas temperature gauges, then sent them out for testing at an independent lab. They were tested for response and accuracy. The ten-page report was written up for the TDR magazine and was published in Issue 34, Fall of ’01.
Way back when, the cliché, “you get what you pay for” proved to be correct. The SPA Technique digital gauge was the top performer. However, it was half-again as expensive and this company is no longer in business. The other EGT gauges were comparable in performance. With comparable performance, the choice becomes one of aesthetics. Gauge evaluator, Jim Wier, wrote, “In regards to the ‘best gauge,’ it is how you view the mechanical installation and how you like the color of the dial.” So, while we may be biased toward a particular brand, the choice is yours.
Since that time (Weir’s article ran in the Fall of ’01), there have not been any revelations in the gauge business. So, really the choice is yours, and the prices (when you add ‘em all up and throw in a mounting pod) are within 10% of one another. Which Auto Meter or ISSPRO fuel pressure gauge will look the best in your truck?
Now, for late model owners, if you have an ‘07.5 or newer truck with its 6.7-liter engine we highly recommend the EDGE “Insight CTS3” unit which simply plugs into the OBDII data port. The data available at the OBDII port gives you 20+ data points.
The Insight also has a host of other features that make it an item worthy of your consideration. For example, the big benefit of the EDGE Insight is that it will allow you to identify fault codes and clear them off. The only drawback of the EDGE Insight: its exhaust gas temperature readings come from factory sensors that are too far downstream to really correlate to the true temperature at the manifold/turbocharger. The EDGE folks do offer a non-expandable EGT probe you can purchase and tap into the exhaust if you want a true EGT number.